Hi !
If you can, you have to test them by yourself. I, for example bought the cannon A710 IS and from the first pic. i was very disappointed from the focus of the camera. I made some comparing test with Olympus C740 using a resulution target and saw some strange things:
The cannon A710 IS had better resolution on target but bad focus on the entirely picture so I think that there is a differ digitall procces algorithem that make differ results. think about that the image that digital camera produces is not only optical as in film still pic cameras.
here are more arguments involved and manufacturers are not telling all details.
Thanks and have Chag Sameach